A slider is an American term for a small sandwich, typically around 2 inches (5 cm) across, made with a bun or dinner roll.

Sliders can be served as hors d'oeuvres, snacks, or entrées.

[1] They have become a popular game day appetizer in the United States.

[2] The name "slider" is believed to have been first used to describe the onion-steamed small burgers at White Castle restaurants.

White Castle likes both stories; they haven’t picked a favorite.